Vacuum Resin Injection – U.S.A

Built in the 1980’s, Bridge 05845 is a Three Span, twin bore box girder pre-stressed segmental concrete design bridge, supported by Two Piers and Two Abutments. The Bridge carries the CD Westbound Roadway over the Interstate 84 highway at Ramp J.

Following a lengthy pre- qualification process, Resitech Limited’s newly formed subsidiary Resitech Special Projects U.S.A LLC was Sub-Contracted by Main Contractor Mohawk Northeast to undertake the Crack Repairs by Vacuum Injection at the above project for the State of Connecticut Department of Transport.

The specification called for all cracks greater than 0.009” (0.23mm) to be sealed using the Vacuum Impregnation Process. This process is a particular speciality of Resitech’s having had over 28 years experience in this type of repair, helping develop the process from its early inception in the late 1970’s up until the present date. Resitech were able to demonstrate their expertise in this field via the previous undertaking of successful contracts of a similar nature here in the U.K.

This contract was a particularly challenging one not least because the works were to be undertaken mainly from the inside of the Box Girders. The only access to the inside of the structure was via a pair of 24” diameter manhole entry points located at each end of the underside of the spans. This meant that the area was designated a Confined Space.

Mohawk Northeast, who were the prime contractor on this project dealt with all of the Health and Safety and Environmental aspects of the work, along with any local regulatory requirements as they came about. This left Resitech to manage the day to day logistical requirements of carrying out the works and the restrictions imposed by the Confined Space Classification.

The records of earlier surveys undertaken were at hand and were referenced to, however Resitech, along with the Connecticut Department of Transports own engineers undertook a detailed condition survey of all existing cracks to the structures. All cracks which fell in to the specified repair criteria were marked up for repair. After careful consideration of the existing site conditions, along with trial injections, an optimum repair material was identified and the main works proceeded on this basis.

Resitech were originally contracted to undertake up to 1140 linear feet of injection works, however the final total exceeded 1480 linear feet. Detailed record sheets were produced to record every single crack injected, along with materials used, quantities, date of injection along with ambient conditions etc. These were submitted to the engineer at the completion of each span for approval and record purposes.

Having successfully completed this contract along with our partners in the USA, we are confident in our ability to undertake future works of a specialist nature overseas. In line with this we will continue to seek out future opportunities in the U.S.A & Worldwide.